As the poster above said, "read the reviews". Amazon is particulary good for this. Here's how I check them:
1. Bring up the review page
2. Click "newest first"
3. Type "command-F" to bring up Safari's search box
4. Type in "mac" and hit return
5. You will be taken to the first page and all examples of "mac" will be highlighted.
6. DON'T use the "down arrow" key to navigate. Instead, use either "page down" or the scroll wheel on the mouse
7. When you get to the bottom of the first page, click "next page"
8. Repeat with "command-F", etc.

Sounds complicated, but it's not. This will quickly find Mac-oriented reviews and skip over the remarks of PC users.